I was recently preparing a paper for an ACS journal and had a few issues with the bibliography style. Most of these were fixed by downloading the latest achemso.bst style file from here. However, it didn’t include that the journal seems to use only first pages (not ranges) when making references. That is, an article on pages 1897–1902 is referred to as:
Authors, Journal, Year, Volume, 1897
Authors, Journal, Year, Volume, 1897–1902.
So, using some information from here I have made a modified achemso.bst that uses only the first page. I don’t know about you but it always takes lot googling to figure out this stuff, so I’ve tried to make this post easily findable by those in a similar situation.